This invention relates to an electrosurgical apparatus for treating tissue and, more particularly, to an electrosurgicai bipolar treating apparatus.
The use of electrosurgery for cutting tissue is known in the art. A typical electrosurgical cutting apparatus comprises a handpiece having an active monopolar electrode which conveys high frequency electrical energy from a generator to tissue at an operational site. The electric circuit is completed through a return electrode attached to the patient.
A monopolar electrosurgical device gives satisfactory performance as long as the circuit is efficiently completed through the return electrode. However, because of possible dangers of electrical current flowing through the patient's body in undefined paths as it is conducted to the return electrode, there has been a growing demand for a bipolar cutting device. A bipolar device is defined as a device which has two electrodes in close proximity to each other as well as to the surgical site and which does not require a patient return electrode for the performance of safe and efficacious electrosurgery.
In a bipolar device, one of the electrodes is defined as the active electrode and the other as the return electrode. The active electrode must be capable of setting up a steam barrier with the tissue and be capable of performing the same operations of cut, blend and coag as a monopolar device. As used herein the term "treating" means the operations of cut, bland and coag.
The return electrode must be capable of returning the current delivered by the active electrode with minimal to no tissue desiccation or destruction at its contact point with the patient's tissue.
Although bipolar instruments are known in the prior art, heretofore manufacturers have focused attention on the generator output stage of units used with monopolar devices and a satisfactory and safe bipolar treating device has not been produced.
It has now been found that a safe and efficacious bipolar treating electrosurgical apparatus is obtained by suitably controlling the configuration and characteristics of the bipolar electrodes.